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The paper presents data on the identification for the first time in Moldova of the helminth fauna structure of Rana dalmatina Bonaparte, 1840, and the determination of its role as bioindicators and as vectors for parasitic agents specific to animals. As result of helminthological investigations, 18 helminths species was established. The predominant group are trematodes with 61.1% of cases, nematodes with 27.7% of cases, acanthocephalan and monogeneans with 5.6% of cases each. According to the assessment of the main helminthological indices, it was established that the species is infested with helminths in 83.3% of cases. When evaluating the data and the composition of helminth species, it was found that adult forms of helminths are predominant over larval forms, so that, when the host species is infected with trematodes, 27.3% are metacercarias, and 72.7% are the adult forms, when the host species is infected with nematodes 20.0% are the larval stages, and 80.0% are the mature forms, when infesting the host species with acanthocephalans and monogeneans, it was established that the helminth species is an adult form, each constituting 5.6%. [ABSTRACT FROM AUTHOR]

Globally, amphibians represent one of the main objects of study in the context of climate change, because the temperature variations recorded and in the Republic of Moldova also represent a major threat to their development and sustainability. For this purpose, a complex ecological study was carried out regarding the embryonic and larval development strategies of the Rana dalmatina Bonaparte, 1840, species and the main particularities related to its population structure and dynamics were described. This research allowed us to evaluate the degree of ecological plasticity of natural populations of Rana dalmatina in relation to the plurality of environmental factors, which allows us to develop suitable and safe measures for monitoring and conservation of the species.

For 29 consecutive years, the populations of three species of brown frogs, Rana arvalis, R. dalmatina and R. temporaria, were monitored in an open area in South Zealand, Denmark, with no direct influence of agriculture. Population sizes were recorded by counting egg clumps and showed large variations from year to year. The total population of R. arvalis differed by a factor of 100 between the years with the lowest and the highest numbers. A total of 19 initially unoccupied suitable waterbodies could potentially be colonised by the frogs. Rana dalmatina colonised all of the ponds, mostly in the very first year of existence. Rana arvalis colonised 17 ponds after an average of 10.5 years. Rana temporaria colonised eight ponds after an average of 13.4 years. Colonisation by R. dalmatina was independent of changes in total population size, whereas colonisation by R. arvalis predominantly occurred in years with considerable population increases. The results are discussed in relation to the movement patterns and philopatry of juvenile frogs of the three species. Juvenile R. dalmatina disperse far from the breeding site, but most individuals return to their natal site. This allows the species to be an efficient coloniser of new waterbodies and, at the same time, to have stable occurrence at the original site. The two other species show a more erratic type of dispersal and especially R. temporaria often shifts breeding site from year to year. [ABSTRACT FROM AUTHOR]

When exposed to predation risk, some amphibian species show innate responses, while others recognize their predators by learning. To explore the role played by each mechanism in the assessment of predation risk, we investigated the effects of embryonic and larval exposure to predator chemical cues on tadpole defensive responses, including behavioural, morphological and life history traits. In the first experiment, agile frog (Rana dalmatina) embryos were exposed to the odour of either native (Aeshna cyanea larvae) or alien (Procambarus clarkii) predators each day from egg collection to hatchling (14 days). Body measures (mass, developmental stage, body length, tail length and tail depth) were recorded at hatching and a behavioural test was conducted to explore tadpole responses to predator cues and the potential interaction with their previous embryonic experience. In general, embryonic conditioning did not affect life history traits, except for a slight reduction in tail depth:length ratio for tadpoles exposed to odonate odours. Controls (embryos treated with water) after hatchling reduced their activity when exposed to gammarid-fed odonate cues, suggesting that responses were at least partially innate. Tadpoles exposed to odonate cues as embryos showed a strong defensive response when exposed to dragonfly kairomones. Tadpoles exposed to gammarid-fed crayfish as embryos showed clear behavioural responses towards the same cue (irrespectively of predator diet). Overall, our results suggest that embryonic exposure may tune the defensive responses of the larval stage and early exposure to naïve stimuli may promote their cautionary associations with predation risk. [ABSTRACT FROM AUTHOR]

Simple Summary: Estimating the abundance of populations is a key task of zoologists, but animal species often are difficult to detect- As a consequence, obtaining estimates of abundance can be problematic. For many frogs, the count of the number of egg clutches is the standard approach. How many egg clutches are missed during these counts? What are the consequences of missing some egg clutches on the estimates of population decline? First, we used the double-observer approach to estimate the detection probability of the clutches of two frog species (the agile frogs Rana latastei and R. dalmatina) and found that, for both species, clutches are very easy to detect. Subsequently, by using simulations, we showed that if the detection probability is very high, such as in this case, assessing if populations are stable or declining is straightforward. The situation is much trickier for species that are difficult to detect. Information on the detection probability of a species can be used to optimize their monitoring strategies. Most animal species are detected imperfectly and overlooking individuals can result in a biased inference of the abundance patterns and underlying processes. Several techniques can incorporate the imperfect detection process for a more accurate estimation of abundance, but most of them require repeated surveys, i.e., more sampling effort compared to single counts. In this study, we used the dependent double-observer approach to estimate the detection probability of the egg clutches of two brown frog species, Rana dalmatina and R. latastei. We then simulated the data of a declining population at different levels of detection probability in order to assess under which conditions the double counts provided better estimates of population trends compared to naïve egg counts, given the detectability of frog clutches. Both species showed a very high detection probability, with average values of 93% for Rana dalmatina and 97% for R. latastei. Simulations showed that not considering imperfect detection reduces the power of detecting population trends if detection probability is low. However, at high detection probability (>80%), ignoring the imperfect detection does not bias the estimates of population trends. This suggests that, for species laying large and easily identifiable egg clutches, a single count can provide useful estimates if surveys are correctly timed. [ABSTRACT FROM AUTHOR]

Aim: Understanding which factors determine the variation in population size across space and time is crucial to plan sound conservation interventions. Amphibians are often characterized by large demographic changes, therefore a better understanding of factors driving these changes could help mitigate their global crisis. We investigated drivers of abundance dynamics of two similar frog species to understand why they met different fates in the same study area. Location: Northern Italy. Methods: In seven different years between 2004 and 2020, we performed repeated counts of egg masses of two similar frog species, the agile frog (Rana dalmatina) and the Italian agile frog (Rana latastei), in 31 wetlands, and used Bayesian models to estimate the relationships between frog abundance and candidate drivers acting at the scale of (i) site: wetland surface, shading percentage and the presence of the invasive red swamp crayfish (Procambarus clarkii); (ii) landscape: forest cover around wetlands; (iii) climate: yearly precipitation and (iv) spatially structured population (SSP): clutch incidence of the focal species and crayfish incidence in the surrounding landscape. Results: The two species showed sharp differences in population size and trends: R. dalmatina was abundant and showed a stable trend throughout the entire study period; R. latastei showed low abundance in the first years and then almost disappeared. The abundance of R. dalmatina was positively related to forest cover, shading, wetland area and precipitation, while negatively related to the occurrence of invasive crayfish at both local and SSP level. R. latastei abundance increased with wetland area and precipitation, while models were not able to detect relationships with other factors. Main conclusions: The high sensitivity to drought and demographic stochasticity could have contributed to the quasi‐extinction of R. latastei in the study area, highlighting that similar species can meet different fates even under the same environmental conditions. [ABSTRACT FROM AUTHOR]

Nanotechnology, as one of the fastest-growing industries, offers many benefits in various fields. However, properties that contribute to its positive effects, in other context, can cause adverse effects to various organisms, such as amphibians. Identifying possible negative effects on its survival is crucial since amphibians are the most threatened group of vertebrates. In that context, we investigated the influence of both nano and bulk copper on embryonic development of agile frog, Rana dalmatina. The embryos were exposed to various concentrations (0.01 mg/L, 0.075 mg/L, 0.15 mg/L or 0.3 mg/L) of either nano (CuO, declared size 40–80 nm) or bulk form (CuSO4·5H2O) for 16 days. Upon the experiment, tadpoles were measured and weighted, then homogenized and their protein, lipid, and carbohydrates content determined, as well as the activity of LDH. Our results suggest stronger negative influence of nano copper to size and weight of tadpoles, and bulk copper on lipid content, while both had strong negative effect on carbohydrates content, and LDH activity. In addition, our results suggest agile frog to be more susceptible to negative influence of both, nano and bulk copper, than commonly used Xenopus laevis. Highlights: Nano copper had stronger effect on size and weight of agile frog. Bulk copper had more effect on lipid content of agile frog. Carbohydrates and LDH activity were negatively influenced by nano and bulk copper. Agile frog is more sensitive to bulk and nano copper than X. laevis. [ABSTRACT FROM AUTHOR]

Amphibian clutches are colonized by diverse but poorly studied communities of micro-organisms. One of the most noted ones is the unicellular green alga, Oophila amblystomatis, but the occurrence and role of other micro-organisms in the capsular chamber surrounding amphibian clutches have remained largely unstudied. Here, we undertook a multi-marker DNA metabarcoding study to characterize the community of algae and other micro-eukaryotes associated with agile frog (Rana dalmatina) clutches. Samplings were performed at three small ponds in Germany, from four substrates: water, sediment, tree leaves from the bottom of the pond, and R. dalmatina clutches. Sampling substrate strongly determined the community compositions of algae and other micro-eukaryotes. Therefore, as expected, the frog clutch-associated communities formed clearly distinct clusters. Clutch-associated communities in our study were structured by a plethora of not only green algae, but also diatoms and other ochrophytes. The most abundant operational taxonomic units (OTUs) in clutch samples were taxa from Chlamydomonas, Oophila, but also from Nitzschia and other ochrophytes. Sequences of Oophila "Clade B" were found exclusively in clutches. Based on additional phylogenetic analyses of 18S rDNA and of a matrix of 18 nuclear genes derived from transcriptomes, we confirmed in our samples the existence of two distinct clades of green algae assigned to Oophila in past studies. We hypothesize that "Clade B" algae correspond to the true Oophila, whereas "Clade A" algae are a series of Chlorococcum species that, along with other green algae, ochrophytes and protists, colonize amphibian clutches opportunistically and are often cultured from clutch samples due to their robust growth performance. The clutch-associated communities were subject to filtering by sampling location, suggesting that the taxa colonizing amphibian clutches can drastically differ depending on environmental conditions. [ABSTRACT FROM AUTHOR]

Background: Batrachochytrium dendrobatidis (Bd) is the causative agent of chytridiomycosis, one of the major causes of worldwide amphibian biodiversity loss. Many amphibians exhibit skin-based chemical defences, which may play an important role against invading pathogens, but whether the synthesis of these chemical compounds is enhanced or suppressed in the presence of pathogens is largely unknown. Here we investigated direct and indirect effects of larval exposure to the globally distributed and highly virulent Bd-GPL strain on skin secreted chemical defences and life history traits during early ontogeny of agile frogs (Rana dalmatina) and common toads (Bufo bufo). Results: Exposure to Bd during the larval stage did not result in enhanced synthesis of the antimicrobial peptide Brevinin-1 Da in R. dalmatina tadpoles or in increased production of bufadienolides in B. bufo tadpoles. However, exposure to Bd during the larval stage had a carry-over effect reaching beyond metamorphosis: both R. dalmatina and B. bufo froglets contained smaller quantities of defensive chemicals than their Bd-naïve conspecifics in the control treatment. Prevalence of Bd and infection intensities were very low in both larvae and metamorphs of R. dalmatina, while in B. bufo we observed high Bd prevalence and infection intensities, especially in metamorphs. At the same time, we did not find a significant effect of Bd-exposure on body mass or development rate in larvae or metamorphs in either species. Conclusions: The lack of detrimental effect of Bd-exposure on life history traits, even parallel with high infection intensities in the case of B. bufo individuals, is surprising and suggests high tolerance of local populations of these two species against Bd. However, the lowered quantity of defensive chemicals may compromise antimicrobial and antipredatory defences of froglets, which may ultimately contribute to population declines also in the absence of conspicuous mass-mortality events. [ABSTRACT FROM AUTHOR]

In this study, a total of 16 Agile frog, Rana dalmatina species preserved in the ZDEU-COMU collection and collected from Çanakkale (4 ♂♂, 4 ♀♀) and Kırklareli (7♂♂, 1♀) were examined to estimate their age and the relationship between age and body size using the skeletochronology method. In addition, both femora and phalanx of the samples were evaluated together. Sexual maturity ages were found to be 2-3 in male and female individuals of both populations. The age ranges from 2-4 in males and 3-5 in females. According to this study, there was a positive correlation between length and age (r=0.740). In addition, no difference was observed in terms of LAG numbers compared to the age rings in the femora and Phalanx bones of the samples. [ABSTRACT FROM AUTHOR]

Rural landscapes can host many protected species that are constantly threatened by agriculture intensification and abandonment of traditional managements. Amphibians are severely affected by both processes due to loss and alteration of aquatic and terrestrial habitats. We monitored the breeding activity of Rana dalmatina in a lowland rural area focusing on spawning sites in open habitats, namely ditches amid traditional arable lands and pastures with varying vegetation features, size, and distances from woodlots. Egg clump density and clump size differed between sites, probably depending on environmental and ecological factors (i.e., larval competition, food availability, and predation). The sites next to woodlots showed the highest clump density (up to 0.718 n/m2). Our observations indicate that the maintenance and correct management of water bodies connected to traditional rural activities can be key to amphibian conservation in agricultural areas.

Actividad reproductiva de la rana ágil Rana dalmatina en una zona rural Los territorios agrícolas pueden ser refugio de varias especies protegidas que, sin embargo, están constantemente amenazadas por la intensificación de la agricultura y el abandono de las prácticas tradicionales. Los anfibios están gravemente amenazados por ambos procesos, a causa de la pérdida y la alteración de los hábitats acuáticos y terrestres. Estudiamos la actividad reproductiva de Rana dalmatina en una zona rural de tierras bajas, centrándonos en los sitios de desove en hábitats abiertos, es decir, zanjas entre tierras arables y pastos con diferente vegetación, tamaño y distancia a las parcelas forestales. La densidad y el tamaño de las masas de huevos difirieron según el sitio, probablemente como resultado de factores ambientales y ecológicos (p.ej., la competición entre las larvas, la disponibilidad de alimentos y la depredación). Los sitios cercanos a los parcelas forestales mostraron la densidad más alta (hasta 0,718 n/m2). Nuestras observaciónes indican que la conservación y el mantenimiento adecuado de las masas de agua destinadas a las actividades rurales tradicionales pueden ser esenciales para la conservación de los anfibios en zonas agrícolas.

We monitored the population size of the agile frog (Rana dalmatina) and the common toad (Bufo bufo) from 2011 or 2012, respectively, to the year 2017 at a syntopic breeding site in the vicinity of Belgrade. Adult R. dalmatina population size had minor fluctuations during the years of study (from 351 to 108 frogs). On the contrary, the adult B. bufo population was widely fluctuating towards decline (from 1158 to 141 toads). In both species, population fluctuations were not significantly related to variation of meteorological parameters (air temperature, humidity, precipitation). Density dependence effects on population size were not detected in either species. Apart from possible effects of climate change, the indicated trend towards decline of the monitored B. bufo population could also be the outcome of common population fluctuations or of increasing anthropogenic impact (vicinity of settlement and agricultural land). More years of monitoring more than one population are required to obtain precise information. Nevertheless, our results seem to be coherent with other studies that recommend conservation action for this species. [ABSTRACT FROM AUTHOR]

Abstract In recent years, relatives (bastrovirus, hepelivirus) of hepeviruses (family Hepeviridae) have been reported in a variety of vertebrate hosts. Preliminary studies indicated that inter-viral family recombination events at the junction of the genomes that encodes non-structural (ORF1) and structural protein (ORF2) were implicated in the genesis of hepeviruses. Using viral metagenomics, next generation sequencing and RT-PCR techniques a genetically divergent hepevirus-like RNA virus was identified and characterized from agile frog (Rana dalmatina) tadpoles living in aquatic environment in three natural ponds (Mélymocsár, Lake Ilona and Lake Katlan) in the Pilis Mountains, in Hungary. The complete genome of the viral strain agile frog/RD6/2015/HUN (MH330682) is 7188 nt long including a 48-nt 5′ and a 122-nt 3′ non-coding region. Sequence analysis indicated that the agile frog/RD6/2015/HUN genome has potentially three non-overlapping ORFs. ORF1 (4740 nt/1579aa) has a hepevirus-like non-structural genome organization and encodes several hepevirus-like amino acid sequence motifs. The ORF2 is a potential capsid protein. The functions of the ORF3 were not predictable. The study virus was present in 18 (46%) of the 39 faecal specimen pools from agile frog tadpoles. The taxonomic position of this novel virus is presently unknown. Highlights • A faecal virome of the amphibian, agile frog, was investigated by viral metagenomics. • A novel RNA virus with hepevirus-like ORF1 genome organization was identified. • The complete virus genome was characterized. • The novel virus was detected in 46% of the faecal specimens from agile frog. • It represents a novel relative of hepeviruses with unknown taxonomic position. [ABSTRACT FROM AUTHOR]

Abstract: Behavioural consistency within and across behaviours (animal personality and behavioural syndrome, respectively) has been vigorously studied in the last decade, leading to the emergence of “animal personality” research. It has been proposed recently that not only mean behaviour (behavioural type), but the environmentally induced behavioural change (behavioural plasticity) might also differ between individuals within populations. While case studies presenting between‐individual variation in behavioural plasticity have started to accumulate, the mechanisms behind its emergence are virtually unknown. We have recently demonstrated that ecologically relevant environmental stimuli during ontogeny are necessary for the development of animal personality and behavioural syndromes. However, it is unknown whether between‐individual variation in behavioural plasticity is hard‐wired or induced. Here, we tested whether experience with predation during development affected predator‐induced behavioural plasticity in Rana dalmatina tadpoles. We ran a common garden experiment with two ontogenetic predation treatments: tadpoles developed from hatching in either the presence or absence of olfactory predator stimuli. Then, we assayed all tadpoles repeatedly for activity and risk‐taking both in the absence and presence of olfactory predator stimuli. We found that (a) between‐individual variation in predator‐induced behavioural plasticity was present only in the group that developed in the presence of olfactory stimuli from predators and (b) previous experience with predatory stimuli resulted in lower plastic response at the group level. The latter pattern resulted from increased between‐individual variation and not from universally lower individual responses. We also found that experience with predation during development increased the predictability (i.e. decreased the within‐individual variation unrelated to environmental change) of activity, but not risk‐taking. In line with this, tadpoles developing under perceived predatory risk expressed their activity with higher repeatability. We suggest that ecologically relevant environmental stimuli are not only fundamental for the development of animal personality and behavioural syndromes, but also for individual variation in behavioural plasticity. Thus, experience is of central importance for the emergence of individual behavioural variation at many levels. [ABSTRACT FROM AUTHOR]

Reports of amphibian declines have highlighted the urgent need for long-term data sets to increase understanding of population changes. To detect population changes in the agile frog Rana dalmatina in Vendée, western France, counts were made of spawn masses over 16 years and road mortalities over 13 years. Long-term trends were evaluated using regression analysis of the logarithmic transforms of annual mortalities and egg masses as dependent variables against year as the independent variable. Tests of the regressions against a 0 hypothetical coefficient, indicative of population stability, gave coefficients that were positive for road mortalities and negative for spawn counts. However, neither was significantly different from 0, indicating a stable population. Further analysis using jackknifing produced a series of pseudo-regression coefficients, which agreed with the true regressions. Results from both datasets were therefore congruent and indicated wide annual fluctuations, with a major increase in numbers between 2009 and 2014. Data from spawn deposition in a recently established pond suggested that the presence of invasive crayfish Procambarus clarkii influenced both deposition sites and long-term population changes. [ABSTRACT FROM AUTHOR]

The “risk assessment hypothesis” considers prey density as an important variable to properly assess the actual level of risk, and predicts that, when the ratio between predator cue concentration and prey density is constant, the level of risk perceived by prey is the same. All previous studies which tested this hypothesis with Anurans manipulated density by placing tadpoles into experimental tubs at fixed group sizes. As predation is a process that produces a progressive decrease in prey density, i.e. “thinning”, prey may respond to the rate of group size reduction rather than the absolute number of conspecifics in a given place at a given time. To test if Rana dalmatina tadpoles perceive the progressive decrease in population density due to predation and are able to use this information to fine-tune anti-predator responses, we combined thinning with a constant cue:density ratio and evaluated how these two types of information affected the level of activity of tadpoles. Our results showed no effect of density reduction on prey level of activity, and thinning did not interact with cue intensity to modify tadpoles’ behaviour. However, we observed no difference in tadpole behavioural responses between treatments with the same cue:density ratio. [ABSTRACT FROM AUTHOR]

Abstract: Red swamp crayfish Procambarus clarkii, a widespread invasive alien crayfish, represents a serious threat for several freshwater species, including amphibians, which are declining at a global scale. As a shared coevolutionary history is the main factor determining the emergence of antipredator responses, Anuran tadpoles may not be able to cope effectively with this introduced predator. We performed two experiments to assess agile frog's (Rana dalmatina) defensive responses to both P. clarkii and native dragonfly larvae (Anax imperator). First, we conditioned embryos (collected from two ponds 30 km away from each other) with predators’ chemical cues to explore possible variation in hatching time caused by predation risk. In the second experiment, to evaluate how predators’ diet affects tadpole behavior, we conditioned tadpoles for a 5‐week period with cues from tadpole‐fed and gammarid‐fed predators and recorded behavioral and morphological responses. Embryos did not alter hatching time in the presence of any predator cue, while tadpoles from both populations strongly reduced activity and visibility when raised in the presence of tadpole‐fed dragonfly larvae. Morphological changes were less straightforward and were induced only in one population, for which broader tails and a slight increase in body size of tadpoles exposed to tadpole‐fed predators were observed. The lack of defensive responses in crayfish‐exposed tadpoles suggests that the spreading of this invasive species in agricultural lowlands of northern Italy may represent a further threat to their conservation. [ABSTRACT FROM AUTHOR]

Severe population declines of amphibians have been shown to be attributed to climate change. Nevertheless, the various mechanisms through which climate can influence population dynamics of amphibians remain to be assessed, notably to disentangle the relative synergetic or antagonistic influences of temperature and precipitations on specific life history stages. We investigated the impact of rainfall and temperature on the egg-clutch abundance in a population of agile frog ( Rana dalmatina) during 29 years (1987-2016) on 14 breeding sites located in Brenne Natural Park, France. Specifically, we examined the influence of environmental conditions occurring during five temporal windows of the year cycle corresponding to specific life history stages. Overall, our results suggest that the year-to-year fluctuations of egg-clutch abundances in Brenne Natural Park were partly dependent on local climatic conditions (rainfall and temperature). Climate seemed to influence breeding frogs during the autumn-winter period preceding reproduction. Spring and summer conditions did not influence reproduction. Additionally, we failed to detect effects of climatic conditions on newly metamorphosed individuals. Other factors such as density dependence and inter-specific interactions with introduced predators are likely to play a significant role in reproduction dynamics of the studied frog populations. [ABSTRACT FROM AUTHOR]

The widespread application of pesticides emphasises the importance of understanding the impacts of these chemicals on natural communities. The most commonly applied broad-spectrum herbicides in the world are glyphosate-based herbicides, which have been suggested to induce significant behavioural changes in non-target organisms even at low environmental concentrations. To scrutinize the behavioural effects of herbicide-exposure we exposed agile frog ( Rana dalmatina ) tadpoles in an outdoor mesocosm experiment to three concentrations of a glyphosate-based herbicide (0, 2 and 6.5 mg acid equivalent (a.e.) / L). To assess whether anti-predator behaviour is affected by the pesticide, we combined all levels of herbicide-exposure with three predator treatments (no predator, caged Aeshna cyanea dragonfly larvae or Lissotriton vulgaris newt adults) in a full factorial design. We observed hiding, activity, proximity to the predator cage and vertical position of tadpoles. We found that at the higher herbicide concentration tadpoles decreased their activity and more tadpoles were hiding, and at least at the lower concentration their vertical position was closer to the water surface than in tadpoles of the control treatment. Tadpoles also decreased their activity in the presence of dragonfly larvae, but did not hide more in response to either predator, nor did tadpoles avoid predators spatially. Further, exposure to the herbicide did not significantly influence behavioural responses to predation threat. Our study documents a definite influence of glyphosate-based herbicides on the behaviour of agile frog tadpoles and indicates that some of these changes are similar to those induced by dangerous predators. This may suggest that the underlying physiological mechanisms or the adaptive value of behavioural changes may similar. [ABSTRACT FROM AUTHOR]

We evaluated whether R. dalmatina females laid their eggs randomly within a pond or preferred particular microhabitats. The same measures were performed in the same area in two consecutive years to determine whether the pattern remained constant over time. In 2003, we observed a significant selection for areas with more submerged deadwood and vegetation, presence of emergent ground and low water depth. However, these results were not confirmed in the subsequent year when none of the microhabitat features measured had a significant effect. Although microhabitat features can strongly influence tadpoles, the temporal variability of habitat at this spatial scale suggests that habitat management could be more effective if focused on a a wider spatial scale.

This study explores the cohort patterns in a size versus time plot of individual metamorphs of Rana tadpoles. This meta-study was based on a number of studies where any of three species of Rana tadpoles were raised in tanks under various treatments (variation in source pond, tadpole density, drying regime, hatching date, food level and competitors). A frequent pattern was found where there was an initial decrease in metamorph size as more slowly developing tadpoles metamorphosed. This negative trend sometimes changed to positive as later metamorphs appeared. The later metamorphs were often as large, or even larger, than those first to metamorphose, giving the plot a U-shaped pattern. Also, a number of field studies of two of the Rana species' were analysed for the same aspect. The U-shaped pattern was much rarer but it did occur. A positive linear slope, rather than a negative one, was also found occasionally. A large number of factors affect the growth and development rates in tadpoles, adaptively and non-adaptively, and thus determine their size at the time of metamorphosis. How these can contribute to the found metamorphosis patterns is discussed. [ABSTRACT FROM AUTHOR]

Reproductive interference can seriously affect the reproductive success of involved individuals and may lead to local exclusion of the competitively inferior species. The components of male competitiveness in direct bodily fights for females have been studied rarely in a heterospecific context. In explosively breeding anuran amphibians, males are often coercive and indiscriminate, which frequently leads to interactions among heterospecific males. We experimentally assessed the competitiveness of male Rana dalmatina (RD) and R. temporaria (RT), two species with overlapping breeding both in time and space. The mating speed of the RD males decreased over the course of the breeding season, whereas RT males retained their swiftness. In addition, the RD males were rarely able to replace the RT males from amplexus with RD females, while takeovers frequently occurred among the RD males. Further, larger RD males were more successful in maintaining amplexus and in achieving takeovers when facing smaller conspecifics. Our results suggest that male body size is important for intraspecific competition among the RD males, but the RT males outcompete the RD males of all sizes, perhaps due to their larger body size. Hence, RT males are likely to be effective satyrs of RD females, because they may lower the reproductive success of the latter. Such interspecific differences in the competitiveness of males may represent an important mechanism that contributes to the arousal of asymmetric reproductive interference between species. Significance statement: Reproductive interference-interactions between species during mating with negative consequences on the fitness of involved individuals-is widespread in nature. Even though differences in the competitiveness of males of interfering species may have severe consequences, competitiveness of males has rarely been studied in an interspecific scenario in vertebrates. Males of anuran amphibians are often indiscriminate and coercive and engage in bodily fights for the possession of both conspecific and heterospecific females, which may often compromise the reproductive success of involved males and females. Here, we demonstrate that interspecific differences among ranid males can be large in the swiftness of pair formation, in the ability to defend the mating position and to perform takeovers. These differences are likely to lower the reproductive performance of the competitively inferior species, potentially leading to its local extinction. [ABSTRACT FROM AUTHOR]

The ecological value and conservation potential of post-mining areas have been increasingly recognized by scientists and conservationists during recent decades. Especially valuable are sites left to spontaneous succession, which constitute habitats with high species diversity, or habitats that serve as refuges for threatened species. In contrast to several other taxa, there is a lack of such evidence for amphibians, despite the assumption that primary succession leads to a more suitable environment for amphibians than does technical reclamation. Therefore, we compared the effects of technical reclamation and spontaneous succession on amphibian presence, species richness, and abundance of the model species Rana dalmatina in technically reclaimed and unreclaimed sections of spoil banks in the Czech Republic's North Bohemian brown coal basin. We found that most recorded amphibian species, and R. dalmatina in particular, occurred predominantly within successional spoil bank sections. Apart from reclamation status, amphibians preferred partially vegetated ponds (5–75% vegetation cover) having gently sloping shores (<30°) and lower water conductivity. Mean species richness per pond (1.95 vs. 1.20), the proportion of ponds occupied by amphibians (88.5% vs. 69.4%), and the mean numbers of R . dalmatina clutches per pond (9.05 vs. 1.65) were significantly higher at unreclaimed sites compared to technically reclaimed sites. This study confirms the conservation value of post-mining sites for amphibians and evidences that sites left to spontaneous succession provide more suitable habitats for amphibians compared to technically reclaimed sites. Key habitat characteristics driving amphibian assemblages within post-mining sites are identified and guidelines for effective protection of amphibians in post-mining areas are proposed. [ABSTRACT FROM AUTHOR]

La población navarra de Rana dalmatina se encuentra fragmentada en 4 núcleos incomunicados, con baja disponibilidad de humedales para la reproducción (entre 2 y 15 por área). La población de hembras adultas fluctúa anualmente entre 1000 y 1500 individuos, sin considerar de la La Barranca, todavía no investigada. La conservación de la especie depende de la gestión de las zonas húmedas.

While the number of studies reporting the presence of individual behavioral consistency (animal personality, behavioral syndrome) has boomed in the recent years, there is still much controversy about the proximate and ultimate mechanisms resulting in the phenomenon. For instance, direct environmental effects during ontogeny (phenotypic plasticity) as the proximate mechanism behind the emergence of consistent individual differences in behavior are usually overlooked compared to environmental effects operating across generations (genetic adaptation). Here, we tested the effects of sociality and perceived predation risk during ontogeny on the strength of behavioral consistency in agile frog (Rana dalmatina) tadpoles in a factorial common garden experiment. Tadpoles reared alone and without predatory cues showed zero repeatability within (i.e., lack of personality) and zero correlation between (i.e., lack of syndrome) activity and risk-taking. On the other hand, cues from predators alone induced both activity and risk-taking personalities, while cues from predators and conspecifics together resulted in an activity - risk-taking behavioral syndrome. Our results show that individual experience has an unequivocal role in the emergence of behavioral consistency. In this particular case, the development of behavioral consistency was most likely the result of genotype × environment interactions, or with other words, individual variation in behavioral plasticity. [ABSTRACT FROM AUTHOR]

The heavy application of pesticides and its potential effects on natural communities has attracted increasing attention to inadvertent impacts of these chemicals. Toxicologists conventionally use laboratory-based tests to assess lethal concentrations of pesticides. However, these tests often do not take into account indirect, interactive and long-term effects, and tend to ignore different rates of disintegration in the laboratory and under natural conditions. Our aim was to investigate the importance of the experimental venue for ecotoxicology tests. We reared tadpoles of the agile frog ( Rana dalmatina ) in the laboratory and in outdoor mesocosms and exposed them to three initial concentrations of a glyphosate-based herbicide (0, 2 and 6.5 mg a.e./ l glyphosate), and to the presence or absence of caged predators (dragonfly larvae). The type of experimental venue had a large effect on the outcome: The herbicide was less lethal to tadpoles reared in outdoor mesocosms than in the laboratory. Further, while the herbicide had a negative effect on development time and on body mass in the laboratory, tadpoles exposed to the herbicide in mesocosms were larger at metamorphosis and developed faster in comparison to those reared in the absence of the herbicide. The effect of the herbicide on morphological traits of tadpoles also differed between the two venues. Finally, in the presence of the herbicide, tadpoles tended to be more active and to stay closer to the bottom of laboratory containers, while tadpole behaviour shifted in the opposite direction in outdoor mesocosms. Our results demonstrate major discrepancies between results of a classic laboratory-based ecotoxicity test and outcomes of an experiment performed in outdoor mesocosms. Consequently, the use of standard laboratory tests may have to be reconsidered and their benefits carefully weighed against the difficulties of performing experiments under more natural conditions. Tests validating experimentally estimated impacts of herbicides under natural conditions and studies identifying key factors determining the applicability of experimental results are urgently needed. [ABSTRACT FROM AUTHOR]

The focus of evolutionary behavioural ecologists has recently turned towards understanding the causes and consequences of behavioural consistency, manifesting either as animal personality (consistency in a single behaviour) or behavioural syndrome (consistency across more behaviours). Behavioural type (mean individual behaviour) has been linked to life-history strategies, leading to the emergence of the integrated pace-of-life syndrome (POLS) theory. Using Rana dalmatina tadpoles as models, we tested if behavioural consistency and POLS could be detected during the early ontogenesis of this amphibian. We targeted two ontogenetic stages and measured activity, exploration and risk-taking in a common garden experiment, assessing both individual behavioural type and intra-individual behavioural variation. We observed that activity was consistent in all tadpoles, exploration only became consistent with advancing age and risk-taking only became consistent in tadpoles that had been tested, and thus disturbed, earlier. Only previously tested tadpoles showed trends indicative of behavioural syndromes. We found an activity-age at metamorphosis POLS in the previously untested tadpoles irrespective of age. Relative growth rate correlated positively with the intra-individual variation of activity of the previously untested older tadpoles. In previously tested older tadpoles, intra-individual variation of exploration correlated negatively and intra-individual variation of risk-taking correlated positively with relative growth rate. We provide evidence for behavioural consistency and POLS in predator- and conspecific-naive tadpoles. Intra-individual behavioural variation was also correlated to life history, suggesting its relevance for the POLS theory. The strong effect of moderate disturbance related to standard behavioural testing on later behaviour draws attention to the pitfalls embedded in repeated testing. [ABSTRACT FROM AUTHOR]

Rana latasteiandRana dalmatinaare two explosive breeder amphibians whose mating seasons last less than 1 month. The two species have very different repertoires of vocalisations, asRana dalmatinauses only one advertisement call whileRana latasteiuses two different vocalisations with opposite structural features. In our research, we continually recorded the calling activity of the two species during a whole breeding season in a pond where they breed in syntopy in order to assess the possible functions of their vocalisations. Males of both species increased their activity in coincidence with the peak of activity of females, butRana latasteimales reached the peak 2–3 days before the deposition peak. By contrast, males ofRana dalmatinareached the peak at the same time as the deposition peak, and called at high intensity long after the deposition peak. These different acoustic patterns led us to infer different prevailing functions for the vocalisations of these species. Male vocalisations ofRana latasteiare addressed only to males in order to gain and confirm their position within male hierarchy. By contrast,Rana dalmatinamales might vocalise also in order to attract females, rather than to deter rival males. Thus, vocalisation in this second species might also play an intersexual function. The two call types ofRana latasteiwere used since the beginning of the breeding season. No difference was found also in daily activity, and both vocalisations were used preferentially during night time. [ABSTRACT FROM PUBLISHER]

The urbanisation process includes three phases: arrival, adjustment and spread. While these are much studied for biological invasions, stage-specific factors promoting successful urbanisation are still poorly understood. In this paper, we study urbanisation of the wood pigeon, Columba palumbus , in Finland. We document the colonisation of the 20 largest Finnish cities; studying how size of the city, geographic location, population density in rural areas surrounding a city, and distance to other previously colonised cities influenced the timing of arrival. We also investigate population development and changes in habitat use during the adjustment and spread stages of the urbanisation process in the city of Turku. We obtained data on wood pigeon observations in inner-city areas from the database of BirdLife Finland, public questionnaires and systematic searches. We found that larger cities and cities located closer to the sea were colonised earlier. Colonisation seemed to be unrelated to both density of rural wood pigeon population and distance to the nearest colonised city. The settlement and spread phases of the urbanisation process followed an exponential curve. No preference for coniferous forest, the habitat type used in rural areas, or deciduous forest was observed. Nests were mainly located in deciduous patches, which are common in cities. We conclude that colonisation of cities by wood pigeons was influenced by geographic location. The hypothesis that avian urbanisation follows the stepping-stone model between neighbouring cities was not supported. Additionally, our results confirm the hypothesis that, during urbanisation, habitat use of species changes from that in rural areas. [ABSTRACT FROM AUTHOR]

Lack of access to safe drinking water remains a present concern in many developing countries, particularly in rural locations. Membrane water treatment technologies have the potential to remove microbiological and chemical contaminants reliably and simultaneously from a wide range of water sources. When powered by renewable energy, these systems are autonomous and have the ability to ‘leapfrog’ over installation of traditional infrastructure for electricity and water supply to reach remote communities. In this paper, current estimated costs for water, membrane plants and infrastructure are compared to indicate the window of opportunity for these exciting renewable energy powered membrane (RE-membrane) technologies. General estimated costs for decentralized membrane systems are within the range of some untreated water costs in developing countries. Specific system costs, however, are very process and location dependent. The appropriateness of a successful approach thus depends partially on careful examination of these parameters. In view of the comparisons made here, the biggest hurdle to adoption of the RE-membrane technology in a remote location may not be cost, but rather sustainability issues such as the lack of skilled personnel for operation and maintenance, service networks, availability of spare parts, socio-economic integration and adaptive capacity of communities to transfer and develop technology appropriate to local needs and circumstances. [ABSTRACT FROM AUTHOR]

Experimental evidence suggests that reproductive interference between heterospecifics can seriously affect individual fitness; support from field studies for such an effect has, however, remained scarce. We studied reproductive interference in 25 natural breeding ponds in an area where two ranid frogs, Rana dalmatina and Rana temporaria, co-occur. The breeding seasons of the two species usually overlap and males of both species are often found in amplexus with heterospecific females, even though matings between heterospecifics produce no viable offspring. We estimated species abundance ratios based on the number of clutches laid and evaluated fertilization success. In ponds with low spatial complexity and a species abundance ratio biased towards R. temporaria, the average fertilization success of R. dalmatina eggs decreased, while this relationship was not detectable in spatially more complex ponds. Fertilization success of R. temporaria did not decrease with increasing relative numbers of heterospecifics. This asymmetry in fitness effects of reproductive interference may be attributed to R. temporaria males being more competitive in scramble competition for females than R. dalmatina males. Our study is among the first to demonstrate that in natural breeding populations of vertebrates interference among heterospecifics has the potential to substantially lower reproductive success at the population level, which may in turn affect population dynamics. [ABSTRACT FROM AUTHOR]

Abstract: Leap frog integration method is a standard, simple, fast, and accurate way to implement velocity and position integration in particle-in-cell codes. Due to the direct solution of kinetics of particles in phase space central to the particle-in-cell procedure, important information can be obtained on particle velocity distributions, and consequently on transport and heating processes. This approach is commonly associated with physical situations where collisional effects are weak, but can also be profitably applied in some highly collisional cases, such as occur in semiconductor devices and gaseous discharges at atmospheric pressure. In this paper, we show that the implementation of the leap frog integration method in these circumstances can violate some of the assumptions central to the accuracy of this scheme. Indeed, without adaptation, the method gives incorrect results. We show here how the method must be modified to deal correctly with highly collisional cases. [Copyright &y& Elsevier]

This paper presents a study of embryonic development, larval and post-larval (metamorphosis) of the frogs of the species Rana dalmatina F. (agile frog) under laboratory conditions. This species has a shrinking population and is declared strictly protected species. Egg collection was made in one of the breeding ponds Gadinti the commune, Neamt County, March 2014. Study, conducted with low material brings valuable data about the conditions of their embryonic, larval and post-larval and possibility of increasing laboratory frogs important aspects for understanding and conserving this species of amphibians. [ABSTRACT FROM AUTHOR]

Many studies have provided evidence that prey adjust their behaviour to adaptively balance the fitness effects of reproduction and predation risk. Nocturnal terrestrial animals should deal with a range of environmental conditions during the reproductive season at the breeding sites, including a variable amount of natural ambient light. High degrees of illumination are expected to minimize those behaviours that might increase the animal detection by predators. Therefore, under habitat variable brightness conditions and in different ecosystems, the above mentioned behaviours are expected to depend on the variation in predation risk. Although moon effects on amphibian biology have been recognized, the direction of this influence is rather controversial with evidences of both increased and depressed activity under full moon. We tested in four nocturnal amphibian species (Hyla intermedia, Rana dalmatina, Rana italica, Salamandrina perspicillata) the effects of different (i) light conditions and (ii) habitats (open land vs. dense forest) on the reproductive phenology. Our results showed that the effects of the lunar cycle on the study species are associated with the change in luminosity, and there is no evidence of an endogenous rhythm controlled by biological clocks. The habitat type conditioned the amphibian reproductive strategy in relation to moon phases. Open habitat breeders (e.g., ponds with no canopy cover) strongly avoided conditions with high brightness, whereas forest habitat breeders were apparently unaffected by the different moon phases. Indeed, for all the studied species no effects of the moon phase itself on the considered metrics were found. Rather, the considered amphibian species seem to be conditioned mainly by moonlight irrespective of the moon phase. The two anurans spawning in open habitat apparently adjust their oviposition timing by balancing the fitness effects of the risk to be detected by predators and the reproduction. [ABSTRACT FROM AUTHOR]

Hotspots of genetic diversity are regions of utmost importance for species survival and conservation, and their intimate link with the geographic location of glacial refugia has been well established. Nonetheless, the microevolutionary processes underlying the generation of hotspots in such regions have only recently become a fervent field of research. We investigated the phylogeographic and population genetic structure of the agile frog, Rana dalmatina, within its putative refugium in peninsular Italy. We found this region to harbour far more diversity, phylogeographic structure, and lineages of ancient origin than that by the rest of the species' range in Europe. This pattern appeared to be well explained by climate-driven microevolutionary processes that occurred during both glacial and interglacial epochs. Therefore, the inferred evolutionary history of R. dalmatina in Italy supports a view of glacial refugia as 'factories' rather than as repositories of genetic diversity, with significant implications for conservation strategies for hotspots. [ABSTRACT FROM AUTHOR]

Se ha estudiado comparativamente la biología reproductiva de Rana dalmatina en dos humadales próximos y no conectados del borde oriental de su distribución ibérica, habiéndose detectado diferentes comportamientos de puesta, interpretables a partir de la diferente estructura de la vegetación en el hábitat reproductivo. El periodo de puestas de 1994 comenzó los días 14 y 10 de febrero, prolongándose durante 19 días y cerca de cuatro semanas, respectivamente. Se contabilizaron 638 y 45 masas de huevos, lo que da idea de grandes diferencias poblacionales, debido a las dispares situaciones que soporta cada humedal y al estado del hábitat que los alberga. No hay periodos de descanso reproductivo en el primer humedal, en el que la media de huevos por puesta es de 718. La actividad reproductiva se inicia masivamente y puede dividirse en dos fases: en la primera, muy activa y que dura la mitad del ciclo, se produce el 88,2% de las puestas ; en la segunda decrece bruscamente, pero no hay interrupciones. La profundidad media de la puesta es de 3,9 cm, en áreas de la orilla dominadas por Sparganium erectum, planta en la que la rana fija el 48.6% de las masas de huevos. En el segundo humedal las puestas quedan libres flotando sobre una pradera encharcada que bordea un denso carrizal. Se comentan unas ideas básicas de gestión de los humedales para la conservación de sus poblaciones de rana ágil.

In this paper, we demonstrate the computational affordability and accuracy of a leap-frog discontinuous Galerkin (LFDG) time-domain method for high intensity radiated fields assessment in electromagnetic compatibility for aerospace. The conformal truncation of the computational domain is discussed and formulated in the LFDG context. Numerical validations are performed on challenging test cases, in comparison to measurements and to other numerical methods, demonstrating the accuracy, efficiency, and scalability of the algorithm. [ABSTRACT FROM PUBLISHER]